Effects of different sour off-flavor in jumbo squid (Dosidicus gigas) on brain perceptions via scalp electroencephalogram and the underlying mechanisms

The commercial utilization of jumbo squid (Dosidicus gigas) faces significant constraints due to its pronounced sour off-flavor. This investigation employed a multimodal approach combining electroencephalography (EEG), electronic sensing technology, and conventional sensory evaluation to characterize the perceptual attributes and neural correlates of varying off-flavor intensities, aiming to explore the underlying mechanisms. Sensory profiling indicated that sour off-flavor of jumbo squid was mainly attributed to the combined effects of sourness, bitterness, and persistent aftertaste. Further analysis using the electronic tongue and electronic nose clarified the distinct characteristics of the squid sour off-flavor at varying intensities. The spectrum analysis of averaged EEG signals revealed robust neural activation patterns, with particularly prominent responses in the δ and α frequency bands. Distinct levels of sour off-flavor elicited clearly different temporal dynamics, with perceptual distinctions emerging within the 0–200 and 950–1500 ms following stimulus onset. Notably, the topographical distribution and source localization results suggested that increasing off-flavor intensity elicited progressively stronger neural activation, with the prefrontal cortex and right temporal lobe showing the most pronounced responses. By employing EEG for comparative analysis of sour off-flavor intensities in jumbo squid, this study provides novel insights into the neurophysiological mechanisms underlying off-flavor perception. Therefore, EEG is proved as a promising objective assessment tool for quantifying subtle flavor variations often missed by conventional sensory panels in seafood quality evaluation.